Same place



(Model.)

G. W. DAVIS.

LATHE CHUCK. No. 297,070. Patented Apr. l5., 1884.

y? lfzg. 4L/ll, /"gf-Y-z//y linrran Srarns GEORGE W. DAVIS, OB NEW BEDFRD, MASSACHUSETTS, ASSIGNOR OF ONE-HALF TO EZEKIEL H. NOBLE, OFW SAME PLACE.

LATHE-CHUCK.

`SPECIE'ICA'IION' forming part 0f Letters Patent No. 297,070` dated April l5, 1884-.

` Application fried December 1s, 1882. (Model.)

Y ina-fter fully described, whereby the chuck can be readily manipulated to form countersunk recesses, both plain and screw-threaded, the countersinking de vices combined with a drill, and the chuck at the same time is capable of being adj Listed to perform the functions of an ordinary chuck.

In the accompanying drawings, Figure l is i a centrahlongitudiual section of a lathe stock v5o From the foregoing it will be apparent that l upon the stock between the screw-threaded ico dogs in said openings.

and chuck on an enlarged scale, illustrating my invention. Fig. 2 is a side view, showing the parts in a different position. Fig. 3 illustrates the parts in detail; and Fig. 4 is a front View of the chuck, the outer shell being removed.

A is the lathe-stock, having a cylindrical head, B, tapered at its front end, b, and screwthreaded along the body of said head. The case G is internally threaded to engage the lathe-stock head B. l Thefront portion, b', of the case C is tapered, and is provided with three openings, C C C, which converge toward each other at the center of the front portion, b, ofthe case C. Each of said openings C C C have the side walls grooved at d. A series of dogs, D, having the body portions c provided with ribs f on each side of said body portion, are adapted to be placed one in each of the openings C C C, so that the ribsff of said dogs lie in the grooves of said openings C C C and prevent the vertical play of said The openings C C' C are inclined from the front b of the case G toward the beveled front portion, b, of the stockhead B, the outer face of the body portion e of each dog being correspondingly inclined, the ribs f thereon and the grooves d in'the case being likewise inclined to admit the ready insertion and withdrawal of the dogs.

as the dogs are moved into the case, cutters h, `secured to extensions i of the dogs, will be caused to approach each other, while the outward movement of the dogs from the case will cause the several cutters to recede from each other. A shell., E, having a conical front portion, F, and cylindrical body portion, is adapted to inclose the case C and the dogs D, so that a tion with the head B thereof, is also threaded l to engage an interiorly-threaded aperture, Z, in the head of a cap, J.

Vhen it is desired to clamp a bit or other boring implement, the parts of my improved` lathe-chuck are organized as shown in Fig. l of the accompanying drawings, the jaws being tightened upon the bit by holding the neck I stationary and turning the case E, which will cause its portion F to bear upon the face a of the dogs, so as to force them upon the bevel portion b of the stock-head of the lathe and upon the bit. lThe same end may be accomplished by turning the case J and the screw-threaded portion B, which will travel within the case C and produce the same results-to wit, force the dogs upon the shank of the bit. The dogs, being provided with cutters L, as shown, will form a countersink, if the article iu which the perforation is made is brought in contact therewith.

In operating the chuck to open or close the jaws, the parts B and J move as one piece, while the other parts move in asimilar manner.

It will be readily seen that when it is desired to remove the bit it may be accomplished by turning the portions B aud J in an opposite direction from which they are"turned to tighten the jaws.

The cap H is held against lateral movement upon the stock by means of the shoulder K portions B and Z. As the stock is turned in the proper direction and the case E held stationary, it will cause the portion C to recede and the dogs to slide rearwardly, so as to allow the bit to be withdrawn. If the case or portion C is advanced'suiiiciently in the head, the cutters will abut against each other and conjointly forni al single tool, which may be cinployed as a centerer.

VW'hat I elaiin as new, and desire to secure by Letters Patent, is- I 1. The combination, in a lathe-chuck, of the stock having a threaded head provided with a front tapering portion, against which hears a series of cutting-dogs, a case traveling on the said head and adapted to exert a downward pressure on the dogs, and a shell concentric with the cap and clamping the dogs a gainst the conical front portion of the head, .and rigidly secured by engaging athreaded cap,against which bears the head, and which is re-ent'orccd by av Second cap secured on the stock, substantially as set forth.

2. The combination, in a lathe-chuck, of a case traveling on a threaded head and having a front conical portion, a series of openings near the center and radiating therefrom, and provided with grooves d, adapted to receive ribs on the body portions of the cutting-dogs which rest snugly in the said radiating openings, and a shell concentric with the said case and adapted to clamp the dogs against the said head and screw-threaded at its rear for engagement with a threaded cap, substantiallyT as set forth.

3. rIhe combination, in a lathe-chuck, of an interiorlythreaded case traveling on the threaded body of the .head of the stock, and having a front conical portion provided with inclined grooved openings adapted to receive inclined body portions of aseries of dogs ribbed as described, and a shell, substantially as set set forth. Y

et. The combination, in a lathe-chuck, of a stoel; having a threaded head, B, a threaded case, C, traveling thereon, and having a conical portion provided with grooved openings inclined to receive inclined ribbed dogs, a shell E, concentric with said case C, and screwthreaded at its rear to engage a threaded cap, H, against the head of which bears the shoulderj ofthe head, and a cap, J, secured to the neck, and re-enforcing the cap H, substantially as set forth.

GEORGE XV. DAVIS. witnesses:

EDWARD J. LUCE, FRANK A. MILLIKEN. 

